Fender assembly

ABSTRACT

A fender assembly to be mounted on the surface of a quay-wall as found in harbors or dockyards comprises two pairs of rubber elements each having a plate like trapezoid shape and a rigid impact receiving plate. The pairs of rubber elements are adapted to be secured on to the surface of the quay-wall so that they form together a frustum of a quadrilateral pyramid widening towards the quay-wall surface. The impact receiving plate is rigidly secured on to the top of the pairs of rubber elements.

United States Patent 1191 Miura 11 1 3,708,988 1 Jan.9, 1973 54 FENDERASSEMBLY [75] Inventor: Misao Miura, Yokohama, Japan [73] Assignee:Siebu Gomu Kagaku Kabushiki Kaisha, Tokyo, Japan 221 Filedi May2l, 197021 Appl.N0.:39,392

[30 Foreign Application Priority Data Sept. 18, 1969 Japan ..44/74459[52] U.S. C1. 1.61/48, 114/219, 256/1, 267/140 [51] Int. Cl. ..E02b 3/22[58] Field 0l SearcIi...61/48; 114/219; 267/140, 141; 293/l,5lF,52F;256/13.1,1

[56] References Cited UNITED STATES PATENTS 3,563,525 2 1971 Narabu..6l/48X 3,533,242 10 1970- Narabu ..61/48 3,335,689 8/1967 1 Hein ..114219 3,507,123 4/1970 Miura ..61/48 FOREIGN PATENTS OR APPLICATIONS1,570,438 5/1969 France ..61/48 1,355,659 2/1964 France ..114/219Primary Examiner-David J. Williamowsky Assistant Examiner-David H.Corbin Attorney-Wenderoth, Lind and Ponack [57] ABSTRACT A fenderassembly to be mounted on the surface of a quay-wall as found in harborsor dockyards comprises .two pairs of rubber elements each having a platelike trapezoid shape and a rigid impact receiving plate. The pairs ofrubber elements are adapted to be secured on to the surface of thequay-wall so that they form together a frustum of a quadrilateralpyramid widening towards the quay-wall surface. Theimpact receivingplate is rigidly secured on to the top of the pairs of rubber elements.

1 Claim, 5 Drawing Figures 1 Kumazawa ..61/48 a PATENTEDJAN 9198INVENTOR ATTORNEY.

FENDER ASSEMBLY BACKGROUND OF THE INVENTION The present inventionrelates to a fender, and more particularly to a rubber fender assemblysuch as to'be installed on the surface of a quay-wall in harbors -ordockyarcls to protect against possible damage to the ship hull due toimpact.

With the size of ships becoming larger and larger, requirementsfordevelopment of fenders with safer and higher performance have recentlybeen mounting. A rubber fender assembly must be able to sufficientlyabsorb the kinetic energy occurring in the case of the ship beingbrought into contact with the quay-wall. Also, the rubber materialsdeformation caused by the impact must be normal and stable. The modernfenders are designed with particular attention to the compressivestresses generated in both the impact receiving surface of the fenderassembly and the outside plating of the ship hull due to the impactforce occurring when the ship comes into contact with the impactreceiving plate of the fender, and it is made prerequisite that thecompressive stress does not exceed the allowable compressive stress ofthe hull. Therefore, in order to reduce the compressive stressgenerating in the fender by enlarging the area of its impact receivingsurface, it is becoming common to adopt such a construction as to mounton it a rigid impact receiving plate.

Such rubber fender assemblies now under use are composed of V- orH-shaped or the like longitudinal hollow rubber tubes with theirlongitudinal directions being disposed in parallel to the surface of thequaywall and a pair of such portions of the rubber tubes thatelastically deform upon receipt of an impact force from the ship when itcomes into contact with the impact receiving surface of the fenderassembly are arranged in parallel to each other, And further, suchrubber fender assemblies arev integrally provided with impact receivingplates in order to reduce the compressive stresses when an impact forceis exerted thereon. However, with such a rubber fender assembly, when itis subjected to a force parallel with its impact receiving plate, thatis, a component ofa force parallel to the longitudinal direction of thesurface of the quay-wall such as generated by a ship when it contacts itobliquely, or a friction force exerting between the impact receivingplate and't he outside plating of the ship hull when the ship is movedalongside the quay-wall-or a force due'to the weight etc. of the impactreceiving plate exerting orthogonally to the longitudinal direction ofthe fender assembly, it easily deforms traversely. Under this condition,if an impact force from the ship is exerted simultaneously on the impactreceiving plate of the fender assembly at right angles thereto, thefender becomes unstable without making normal deformation. Accordingly,the fender assembly cannot absorb the kinetic energy as required,resulting in a reduction in its performance, possibly to be followed bydamage to the hull.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an improvedfender assembly to be installed on the surface of thequay-wall of a harbor or dockyard which does not have thesedeficiencies.

A further object of the present invention is to proi vide a rubberfender assembly which can sufficiently absorb the kinetic energy of theship when it is to be tied up alongside the quay-wall and thedeformation of the rubber elements constituting part thereof caused bythe ships contact with the quay-wall is normal and stable.

Another object of the present invention is to provide a rubber fenderassembly which does not easily deform laterally when it is subjected toan oblique force relative to the direction of its impact receivingplate, and deforms normally even when it is simultaneously subjected toan impact normal to its impact receiving plate. 7

The rubber fender assembly of the present invention is preferablycomposed of two pairs of rubber elements each generally having a platelike trapezoid shape and an impact receiving plate made of a rigidmaterial such as steel plate; Each rubber element constituting therespective pairs of rubber elements is adapted to be secured on thesurfaces of the quay-wall oppositely to form together a frustum of aquadrilateral pyramid widening towards the surface of the quay wall. Theimpact receiving plate is adapted to be secured to the upper ends of therubber elements so that its outerface is parallel to the surface of thequay-wall. Thus, in the rubber-fender assembly according-to the presentinvention, even when it is subjected to an impact having a componentparallel to the impact receiving plate, a shearing elastic resistiveforce is exerted on to the ship from some of the rubber elementsregardless of the fender assembly being mounted in a longitudinaldirection or a transversal direction relative to the direction of thequay-wall, because, sinee, in the present fender assembly, four rubberelements are disposed orthogonally to each other so that they form afrustum of a quadrilateral pyramid widening towards the surface of thequay-wall, there always exists at least one pair of rubber elementswhich are disposed to be deformed in the direction of said parallelcomponent. Accordingly in this case, the fender assembly behaves as ifits impact receiving plate were applied 'with only an impact orthogonalthereto, as the result of which the quantity of the absorbing energy isnot reduced as in the conventional fenders and it worksat its maximumcapacity. Further, since the fender assembly according to the presentinvention has its four rubber elements made to generally form" a frustumof a quadrilateral pyramid widening towards the surface of thequay-wall, it is highly stable against the external force regardless ofits direction.

in addition, in the fender assembly according to the present invention,the construction for mounting the impact receiving plate is such that itcauses the impact receiving plate to act as a bidirectional boardsupported at four sides by four rubber members unlike the impactreceiving plate of conventional fenders which acts as a monodirectionalboard supported at two sides. Accordingly, the modulus of section of theimpact receiving plate of the rubber fender assembly according to thepresent invention can be reduced by about 40 percent or more comparedwith that of the conventional ones.

-in connection with the accompanying drawings,

wherein there is set forth by wayofillustration an embodiment of thisinvention. In the drawings:

FIG. 1 is a front elevational vijwof a rubber fender assembly accordingto the present invention, partially broken away;

FIG. 2 is a side elevational view of the fender assembly shown in FIG.1';

FIG. 3 is a sectional view of the fender assembly shown in FIG. 1 takenalong the line III-III of FIG. 1;

FIG. 4 is a partial sectional view of the rubber element constitutingpart of the fender assembly shown in FIG. '1 taken along the line lV.lVof FIG. 1, in a larger scale; and

FIG. 5 is a view similar to FIG. 4, but taken along the line V--Vof FIG.1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 to 3, thefender assembly of the present invention comprises two pairs of rubberelements 1 and 2 and an impact receiving plate 3. Each of the rubberelements 1 and 2 has a-plate like trapezoid shape and its, upper end isformed witha L-shaped abutment 4 at its inner side in order to be'adapted to mount the impact receiving plate 3 when assembled, while atits'flat bottom portionthere are formed an inner. longitudinal flange 5and outer lugs 6,6 both beingadapted toimount it on the surface of aquay-wall 7. Ribs 8 and 9 form the upright and horizontal walls ofabutment 4;Flanges 5 as well as lugs 6 are all provided withone or moreholes to. pass bolts 10 therethrough for securing the rubber elements 1and 2 to the surface of the quay-wall 7. The impact receiving plate 3 ismade of rigid material such as steel or the like and has rubber elements1 and 2 is disposed oppositely so that the rubber elements 1 and 2define together a frustum of a quadrilateral pyramid widening towardsthequaysaid abutments.

wall surface, the impact receiving plate 3 is mounted on the tops of therespective rubber elements I and 2 with its bottom stepped surface 11being mounted on abutments 4 formed on the upper ends of the respectiverubber elements 1 and 2 The plate 3 is rigidly secured by bolts 12screwed into it through upright ribs 8 and horizontal ribs 9 of therespective rubber elements 1' and 2. I

As shown in FIGS. 4 and 5, each of the rubber elements 1 and 2 hasembedded therein L-shaped and flat metal braces 13 and 14 forreinforcing abutment 4 and flange 5, whereby the braces. 13 and 14 areformed with bolt holes to facilitate the insertion of the fasteningbolts 10 or 12.

It will be appreciated that the L-shaped metal brace 13 has its uprightrib disposed along the outside surface of the rubber elements 1 or 2 soas not to prevent them from deforming when impacted from ships,therebyensuring that the deformations of the rubber elements 1 or 2 aremade large.

While there has been described andillustrated herein a preferredembodiment of the invention, it will be understood that other changesand modifications can be made in the present invention andtherefore itis understood that all changes, equivalents, and modifications withinthe spirit and scope of the present invention are here meant to beincluded in the appended claims.

What is claimed is: I. A fender'assembly attached to the surface of aquay-wall in a harbor or a dockyard, said assembly comprising a firstpair ofdeformable elements mounted at the lower portions thereof on saidsurface parallel to each other; a second pair of deformable elementsmounted at the lower portions thereof on said surface parallel to eachother and orthogonal to said first pair of elements; each-of saidelements having a plate-like trapezoid shape; said first and secondpairs of elements mounted symmetrically on said surface to definetogether a frustum of a quadrilateral pyramid widening toward saidsurface; the upper portions of each of said elements includinghorizontal and vertical ribs forming an L-shaped abutment; the abutmentsof each "of said pairs of elements facing each other; each of said L-shaped abutments having imbedded therein anL- shaped metal brace forreinforcing said respective abutment; and a rigid impact receiving platesecured to

1. A fender assembly attached to the surface of a quay-wall in a harboror a dockyard, said assembly comprising a first pair of deformableelements mounted at the lower portions thereof on said surface parallelto each other; a second pair of deformable elements mounted at the lowerportions thereof on said surface parallel to each other and orthogonalto said first pair of elements; each of said elements having aplate-like trapezoid shape; said first and second pairs of elementsmounted symmetrically on said surface to define together a frustum of aquadrilateral pyramid widening toward said surface; the upper portionsof each of said elements including horizontal and vertical ribs formingan L-shaped abutment; the abutments of each of said pAirs of elementsfacing each other; each of said Lshaped abutments having imbeddedtherein an L-shaped metal brace for reinforcing said respectiveabutment; and a rigid impact receiving plate secured to said abutments.